/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.ambari.server.api.predicate;
import java.util.Collection;
import org.apache.ambari.server.controller.spi.Predicate;
/**
* Compiler which takes a query expression as input and produces a predicate instance as output.
*/
public class PredicateCompiler {
/**
* Lexer instance used to translate expressions into stream of tokens.
*/
private QueryLexer lexer = new QueryLexer();
/**
* Parser instance used to produce a predicate instance from a stream of tokens.
*/
private QueryParser parser = new QueryParser();
/**
* Generate a predicate from a query expression.
*
* @param exp query expression
*
* @return a predicate instance
* @throws InvalidQueryException if unable to compile the expression
*/
public Predicate compile(String exp) throws InvalidQueryException {
return parser.parse(lexer.tokens(exp));
}
/**
* Generate a predicate from a query expression.
*
* @param exp query expression
* @param ignoredProperties collection of property names to ignore
*
* @return a predicate instance
* @throws InvalidQueryException if unable to compile the expression
*/
public Predicate compile(String exp, Collection<String> ignoredProperties) throws InvalidQueryException {
return parser.parse(lexer.tokens(exp, ignoredProperties));
}
}